Air tests taken to identify source of Wednesday's stinky air

Air quality experts ran tests Thursday in an attempt to identify what caused a widespread and pungent chemical odor that prompted nose-wrinkling and head-scratching throughout the San Diego area but caused no known harm.

Technicians with the county Air Pollution Control District took atmospheric samples in several communities as the odd funk, generally described as akin to some sort of petroleum-based substance, was hanging over the region on Wednesday, according to Jon Adams, chief of compliance for the agency.

We've definitely documented the odor, but we haven't to date been able to determine the source,'' Adams said.

District officials hope to isolate the cause of the stink — which apparently originated around the coastal North County before spreading to the south and east during the afternoon and early evening — by as early as Friday, he said. Some reports came from La Jolla and the Torrey Pines area.

The first reports of the mystery odor came from Del Mar and Solana Beach about 1 p.m., Adams said. Over the next six or seven hours, dozens of people made 911 calls about the phenomenon, first in areas near the ocean and then throughout the county.

No one reported any ill health effects from whatever was causing the stench, authorities said.

County personnel checked with the Coast Guard, Lindbergh Field, Camp Pendleton, North Island Naval Air Station and other government agencies, and none had any insight into what might have been behind the foul smell, according to Adams.

So we're kind of at a loss right now as to a source,'' he said this afternoon.

The air-pollution agency's screenings should be able to at least narrow down the cause of the malodorous but invisible fumes, providing a fingerprint'' of the responsible substance or compound, Adams noted. Such findings might not directly reveal the source, but could point investigators in the right direction, he said.

Adams described the pervasive pall as an unusual happening.

"On occasion things like this happen, but it's pretty rare to this level,'' he said. To impact such a wide area, that's pretty rare.''